I'm excited for these fins! In particular the foot pocket and adjustable spring strap! The thing that holds me back from buying these is they are said to be positively buoyant in saltwater. In some other post you mentioned you have a negatively buoyant version of the Eddy fin coming soon. Can you say how it will compare to the current Eddy fins in terms of weight and buoyancy?
I'm having buoyancy issues with my floaty Seawing Novas (in a 7mm wetsuit, single tank), and my girlfriend is as well. I've tried Jet Fins (XL, size 10.5 wetsuit boot and a 10.5 Oceanic thick-soled boot) and found the fit to be poor. The pocket is too wide, even with thicker-soled boots, but not tall enough to allow the foot to go all the way in, so it feels like I'm finning with my toes instead of my whole foot, and the fin wobbles side to side. The key feature I'm looking at on the Eddy fins is a natural fit and extended heel support ledge. The Eddy seems to match the Seawing Nova design or Hollis F1 so I'm looking forward to trying it.